The newly reconstituted Advisory Committee on Immunization Practices panel will hold its first meeting on Wednesday, just weeks after the health and human services secretary’s wholesale firing of all 17 board members, replacing them with just eight individuals, many of them with histories of vaccine skepticism, in what will be the first test of just how far Robert F. Kennedy Jr.’s history of anti-vaccine views will shape United States policy.

There is already cause for concern among those in the medical community and the Senate that the meeting, as currently organized, will discourage vaccinations by highlighting the risks through unvetted presentations from noted vaccine skeptics.

An updated draft agenda for the meeting shows ACIP will vote on maternal pediatric respiratory syncytial vaccines. There will also be presentations, followed by a vote, on influenza vaccines, containing thimerosal, a mercury-based preservative used to prevent microbial growth. 

Thimerosal has been in the crosshairs of vaccine critics for years — Mr. Kennedy himself speculated in a 2014 book that it is “immensely toxic to brain tissue” and could cause neurodevelopmental disorders like autism and ADHD, claims that have been repeatedly debunked. 

The Children’s Health Defense president emerita, Lyn Redwood, is expected to deliver a presentation “regarding thimerosal in vaccines,” according to the final agenda. 

Ms. Redwood is a co-author of the report “Autism: A Novel Form of Mercury Poisoning,” which argued that excessive exposure to thimerosal, “a major source of mercury in children” via vaccinations, can cause neurological disorders similar to autism. The Children’s Health Defense is a controversial nonprofit formerly chaired by Mr. Kennedy that has been outspoken on the issue.

The Vaccine Integrity Project said that Ms. Redwood’s presentation was not vetted by CDC subject matter experts, adding that it was among the many “troubling” recent changes to the ACIP protocol.

Last year, while appearing on Mr. Kennedy’s podcast, Ms. Redwood shared her concerns about administering the flu vaccine to pregnant women and the potential neurodevelopmental harm doing so can cause the fetus. 

On Tuesday, the Centers for Disease Control and Prevention released a new report on thimerosal and neurodevelopmental outcomes, saying it “found no evidence of harm from the use of thimerosal as a vaccine preservative, other than local hypersensitivity reactions.”

ACIP traditionally establishes recommendations for the CDC on vaccine policy, including setting the list of vaccines for the childhood vaccination schedule. ACIP’s recommendations are tied to federal policies and programs like the Vaccines for Children program, which provides free shots to families that may not be able to afford them. 

In recent weeks, Mr. Kennedy’s administration has seemingly whittled away traditional CDC guardrails that were part and parcel of the standard ACIP meeting. Earlier this month, Mr. Kennedy removed a CDC official, Melinda Wharton, and her team at the CDC’s Center for Immunization and Respiratory Diseases from their roles overseeing the ACIP board. Dr. Wharton had served as the executive secretary, which involved, among other duties, vetting ACIP nominees, setting the meeting agenda, and coordinating meetings for ACIP’s work groups that review published and unpublished data and offer recommendations for board members. Those work groups have reportedly been removed from the upcoming ACIP meeting.

The newly appointed ACIP chairman, Martin Kuldorff, an outspoken critic of Covid-19 vaccine mandates and one of Mr. Kennedy’s handpicked board members, is set to deliver opening remarks and provide an “update” on the work groups at the start of Wednesday’s meeting, according to the agenda.

A Republican senator of Louisiana who is chairman of the Health Committee, Bill Cassidy, called on Mr. Kennedy to delay this week’s ACIP meeting over the perceived lack of experience of the new panel board members.

“In particular, some lack experience studying new technologies such as mRNA vaccines, and may even have a preconceived bias against them,” Mr. Cassidy posted on X. He said the meeting should be delayed until the panel is completely staffed with “more robust and balanced representation – as required by law.”

During an appearance at a budget hearing before a House subcommittee Tuesday, Mr. Kennedy defended his decision to remove all 17 members from the previous ACIP panel, calling them “a template for medical malpractice.”

During the budget hearing, the Representative Kim Schrier, a Democrat of Washington, accused Mr. Kennedy of lying to Mr. Cassidy by failing to make good on a promise he had made to the senator to maintain ACIP “without changes” prior to Mr. Kennedy’s confirmation.

“I didn’t see that statement by Senator Cassidy. I’ve only heard it from you, but if he said that I agreed to it, it would be inaccurate. I made an agreement with him, and he and I have talked many times about that agreement,” Mr. Kennedy replied during the hearing.

Mr. Kennedy’s recent appointments of the eight ACIP board members were “made without clear rationale, may roll back the achievements of U.S. immunization policy, impact people’s access to lifesaving vaccines, and ultimately put U.S. families at risk of dangerous and preventable illnesses,” the 17 ACIP board members wrote in the Journal of the American Medical Association after their dismissal.

Dr. Kulldorff is also scheduled to present “proposed recommendations regarding thimerosal containing influenza vaccine,” and to deliver a presentation on the measles-mumps-rubella-varicella vaccine in children ages 4 and under, followed by his proposed recommendations for the MMRV shot.

Dr. Kulldorff, a former professor of medicine at Harvard Medical School, co-wrote the “Great Barrington Declaration” with Jay Bhattacharya, now director of the National Institutes of Health. The 2020 open letter argued that mass lockdowns and school closures were doing more harm than good, advocating instead for “focused protection.”

He called Covid vaccine mandates “unscientific and unethical.” He claimed he was dismissed by both Harvard and Mass General Brigham, where he worked as an epidemiologist, for refusing to follow their respective vaccine mandates.

In response to Mr. Kennedy’s recent moves, the Center for Infectious Disease Research and Policy at the University of Minnesota in Minneapolis announced this week it is positioning its Vaccine Integrity Project as a standalone vaccine committee to establish vaccine recommendations. 

The CIDRAP director, Michael Osterholm, said he is already discussing vaccine recommendations with public health groups and medical organizations that include the American Academy of Family Physicians and the American Pharmacists Association.

Mr. Osterholm believes that ACIP may soon no longer be the singular authority that health insurance companies look to for which vaccines should receive coverage. New initiatives like his, he thinks, could “sway insurance companies on which shots to cover.”

Wednesday’s meeting is scheduled to start at 10 a.m.